Alarm device



I Ma 31,1927.

Q 1,630,808 E. T. SIEGERDT ALARM DEVICE Filed Nov. 27, 1925 Z72 verzzr'Patented May 31, 1927.

UNITED STATES ERICK T. SIEGERDT, OF CHICAGO, ILLINOIS.

ALARM DEVICE.

Application filed November 27, 1925. Serial No. 71,637.

This invention relates to alarm devices and is particularly adapted tobe used in connection with wire screens.

In apartment houses, particularly on the second and third floors, it isquite common for children in playing around open windows in the summertime to press their heads against the screens in an endeavor to seesomething outside the apartment. In doin so, they often exertconsiderable force upon the screen, thereby disloding it from itsfastenings and causing the screen and child to fall out of the window.

An object of the present invention is to provide a screen which willgive a warning of this danger.

Another object is to provide a screen with an alarm device attachedthereto which will give notice that an attempt is being made to cut themetal of the screen.

These and other objects are accomplished by this invention which isfully described in the following specification and shown in theaccompanying drawing, in whichplugs with Figure 1 1S a partial outsideview of a window screen embodying the invention;

Fig. 2 is a partial inside view of the same; and

Fig. 3 is an enlarged section on the line 3 of Fig. 2.

The embodiment illustrated comprises a frame on the outside of which issecured a metal wire screen 11 as by means of nails 12. A. recess 13 ispreferably formed 011 the inner face of the frame 10 to which a similarmetal screen 14L is secured as by means of nails 15 preferably placednear the outer edge of the screen.

Over this is placed a strip 16 which is preferably secured to the frameby means of screws 17 placed near the inner edge of the frame 10. Thepurpose of this will later be explained.

A metal socket 18 is carried by the frame 10 and makes electricalcontact with the outer screen 11 while a metal. socket i9 is similarlycarried by the strip 16 and is in electrical contact with the innerscreen 14. Wires 20 and 21 are connected by suitable the sockets 18 and19, respectively, and these are placed in series with an electricalsource of current 22 as a battery, a switch 23 and an electric bell 24,or other form of electrically operated signal apparatus.

From the foregoing, it will be apparent that should a child leaning outof the window press against the inner screen 1%, this screen will beforced toward the screen 11, and when the pressure becomes great enough,will cause the two screens to make contact, thereby causing the bell 2 Lto sound (assuming, of course, that the switch 23 is closed), and thusannouncing the fact that the child is in danger of falling out of thewindow.

After a number of such stretchings of the inner screen 14, it may becomesomewhat loose and to tighten it I have made the ledge 13 slightlybeveled so that when the screen is first stretched, it may have atendency to stand away from the outer corner 13. To stretch the screenit, therefore, it is only necessary to tighten the screws 17 when thedifference in dimension due to the beveling of the ledge 13 will causethe screen 14 to be stretched.

The inner edge of the frame 10 is preferably ridged as at 10 to preventwater falling thereon from short-circuiting the screens 11 and 14.

This device can also be used on screen doors and windows for thedetection of burglars. l Vhere the screen door or window cannot readilybe raised, it is common for them to cut the screen with a knife and, indoing so, the knife blade will make contact with both screens 11 and li, thereby closing the circuit through the battery and bell when thebell 2% will be made to ring.

l'Vhile I have shown and described but one embodiment of my invention,it will be understood that it is capable of many modifications. Changes,therefore, in the construction and arrangement may be made which do notdepart from the spirit and scope of the invention as disclosed in theappended claim.

\Vhat I. claim as new, and desire to secure by Letters Patent, is:

A circuit closing device for alarm systems comprising a frame, twoparallel normally separated metallic screens carried by said frame andinsulated from each other, the frame having a. recess adapted to receiveone screen, the bottom of the recess being inclined toward the otherscreen, a strip adapted to fit into said recess, and means fortightening said strip on the screen to stretch the screen.

ERIGH T. SIEGERDT.

